The president and his choice for secretary of State have forged a close relationship based on trust and shared values, associates say.

WASHINGTON — Official Washington has seldom seen a relationship between a president and a member of his staff as close as the one between George W. Bush and Condoleezza Rice, his first-term national security advisor and now his choice for secretary of State.

What is less obvious is how this relationship came to pass -- and why it seems to have grown stronger, more trusting and more symbiotic through years of cutthroat political campaigning, foreign policy crises, national calamity and war.

Their backgrounds could hardly be more different: Rice, 50, the daughter of a black preacher, grew up in Birmingham, Ala., amid protest marches and Ku Klux Klan violence. Bush, 58, grew up heir to one of America's WASP fortunes, a Skull and Bones aristocrat who followed his ancestors to Yale and then went to Harvard for good measure.

Yet close friends, government colleagues and others who know Rice and the president see threads of common experience and shared values and attitudes that seem to have drawn them together.

"The main element is trust," said a close associate who has watched Rice and the president work together firsthand and spoke on condition of anonymity. "I've worked for a lot of top executives. When they don't trust you, they don't call you. He calls her all the time."

Rice's ability to become an almost clone-like extension of the president -- to understand what he wants, to make her only agenda his agenda and to carry out his wishes with unfailing loyalty -- has made her invaluable.

"The president does rely on her. If she's not literally the first person he talks to every morning, it's close," said Coit D. Blacker, one of Rice's closest friends, who worked with her during her time as provost at Stanford University. "I think that will continue. They're deeply influential on each other.

"Condi," Blacker said, "came in with some academic textbook notions of how foreign policy works. Bush relies on his instincts; his policy is morally grounded. People think she's done a switch.... Those people don't know her. She's the daughter of Rev. John Wesley Rice, a Presbyterian minister. She's always placed high importance on morality and values and personal integrity."

One key to Rice's value to the president is her ability to translate his moral instincts into practical foreign policy, said Abraham D. Sofaer, a senior State Department official in the Reagan administration. Sofaer was part of a foreign policy briefing team that Rice led when then-Texas Gov. Bush began to plan his first run for the White House.

"What the president leans on Condi for is her analytical ability," Sofaer said. "It's one thing to have values and opinions, but it's another to apply them to a problem. It takes skill and diligence, and she's really good at that."

Wherever she goes and whomever she's talking to, admirers and critics agreed, Rice has exercised unusual power because she has had only one agenda and spoken in only one voice: the president's.

"You don't get the tension you had with [Henry S.] Kissinger, who had his own agenda," said former House Speaker Newt Gingrich (R-Ga.), comparing Rice to President Nixon's legendary national security advisor and secretary of State.

Kissinger exercised extraordinary power but never submerged his own ideas and ambitions -- as associates said Rice had.

On Capitol Hill, Democrats and Republicans said that when she spoke, it was Bush's positions she expressed. Indeed, Sen. John D. "Jay" Rockefeller IV (D-W.Va.) complained that even in secret briefings, she never deviated from the White House line.

Others agreed.

"She is remarkably effective in being a very attractive mirror for whomever she is working with," said a foreign policy specialist who had known Rice for 20 years and who spoke on condition of anonymity.

"It's not just that she knows how to adjust and absorb," the foreign policy specialist said. "She manages to develop a relationship of trust in the process. She's not a sycophant, but she knows how to be effective in promoting her case."

For some who know Bush and Rice, the closeness between them goes beyond policy and principles. Different as their backgrounds are, their personalities have been forged in similar fires.

Both have experienced the pain of being looked down on by their peers. Growing up, even his parents never saw George W. as the son who would do great things. It was his brother Jeb, now governor of Florida, who was expected to become the second President Bush.

As a mediocre student and flailing businessman, George Bush got little respect. Even as president, he has been mocked for his occasionally mangled use of English and his reputed disdain for the details of policymaking.

Rice grew up in a brutally segregated city, but made her way not only as a student but as an athlete -- a black figure skater in an almost purely white sport.